Application of genetic tagging for the
management and conservation of European
lobster Homarus gammarus stocks
DNA profiling
Paulo A. Prodöhl
&
Deborah Bailie
Outline
• Lobster biology, V-notching schemes & how we
got started…
• DNA profiling/Genetic tagging: “the theory”
• North East Lobster Co-op (NELCO)“genetic” V-
notching scheme
• Results and implications for conservation &
management
Why lobsters?
Outline
• Homarus gammarus (European lobster)
• Long lived species 20-50 years
• Nocturnal, benthic, sedentary (home range 2-10km)
• Females spawn biannually/annually (size dependent) -
eggs carried ~1 year
• Pelagic phase: 2 – 3 weeks (high potential for dispersal)
• 1st 3 - 4 years lifespan cryptic
• Maturity takes 4-8 years?
V-notching schemes
• V-notching: female lobsters carrying eggs (berried) are
marked with a small notch, and subsequently returned
to sea (same location)
• Individuals legally protected =
increased egg output
• “Potential” benefits to
recruitment and long-term
stock sustainability
• Existed for nearly 100 years!
V-notching scheme – Northern Ireland
• Volunteer or supported through grant aid schemes to
local lobster fishermen willing to participate
• Fishermen get financial compensation to mark and
release egg bearing females to the sea
• Conditional: implementation of appropriate monitoring
mechanisms (good practice) to ensure that the V-
notching is being carried out properly
V-notch
V-notching scheme – Northern Ireland
• Participants bring egg berried lobsters ashore for V-
notching under scrutiny of a fishery officer
• Procedure means that egg carrying lobsters were
often removed from local habitat and kept in cages
• Complex/expensive logistics; approach has also been
linked to substantial egg loss, undue stress, and even
the death of lobsters
• Fishermen in general not particularly happy!
How we get started - EU GEL project 1998
• N > 4,150 (51 sites)
• Project aims: genetic marker
development (microsatellites),
population structure; mating system;
evaluation of genetic tagging (DNA
profiling) – stock assessment
• In 2003 NELCO approached QUB to
investigate the possibility of employing
genetic tagging (DNA profiling) as
suggested in GEL Website as a tool to
monitor NELCO V-notching programme
www.qub.ac.uk/bb-old/prodohl/GEL/gel.html
Microsatellite DNA profiling/Genetic tagging
• A forensic based technique that allows for the
unequivocal identification of individual to families
• No two individuals within outcrossing populations
share the same microsatellite DNA profile
• Individual “DNA fingerprinting”
• Ideal tool for monitoring and
assessing the impact of V-
notching on local stocks
Microsatellite DNA profiling/Genetic tagging
• Approach: sampling/preservation of V-notch and
eggs from individual females
• Examination of the maternal genetic profile (DNA
extracted from the V-notch) alongside that of the
offspring (DNA extracted from fertilised eggs) enables
the paternal contribution to be precisely identified
Identification of individuals to families
Identification of individuals to families
X
Genetic tagging
• Monitoring tool: no two individuals share the same
genetic profile (eggs have to share half of the
maternal genetic profile)
• Fishery Applied Research: if family genetic
information is recorded into a database, it is then
possible to subsequently test whether an unknown
individual from the fishery belongs to any of the
families existing in the database (i.e. V-
notched/genetically tagged families)
• How effective is the V- notching scheme?
NELCO V-notching genetic programme
• First grant award to NELCO (2003): EC- Building
Sustainable Prosperity Programme
• Protocol: from each berried female: V-notch + ~20 -
100 eggs removed and stored
• Individuals returned to sea immediately: reduced egg
loss
• V-notches & eggs sent for QUB
Summary of NELCO scheme
• Genetic screening commenced in 2003 (~40 boats)
• avg. 2,206 lobsters/year (1 for each 6 landed lobsters)
• In 2014, the NELCO database was
comprised of >26,400 genetically
tagged families
• Assuming 10,000-15,000 eggs =
~265 – 397M tagged individuals
• One of the most comprehensive
multi-generation family genetic
database for any marine species
Summary of NELCO scheme
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Total
Jan 88 7 14 11 41 100 394 655
Feb 21 9 6 304 27 98 136 23 624
Mar 43 87 206 117 252 151 229 38 1,123
Apr 202 181 168 194 40 64 350 1,199
May 150 179 605 409 130 926 76 10 2,485
Jun 408 317 125 195 10 149 322 323 293 235 85 2,462
Jul 178 238 280 111 269 40 298 164 600 112 176 2,466
Aug 198 322 58 29 410 147 319 308 357 762 374 3,284
Sep 275 434 372 47 291 962 412 205 167 582 58 346 4,151
Oct 287 129 319 26 414 282 264 30 287 611 302 183 3,134
Nov 127 139 449 412 178 471 208 141 330 534 405 3,394
Dec 49 309 179 21 8 99 305 185 329 12 1,496
Total 1,672 2,312 2,676 1,309 1,821 2,124 3,773 1,802 2,497 3,585 1,968 934 26,473
• Samples screened for a panel consisting of 13 microsatellite
marker loci
• Power analysis = 99% probability of assignment to correct family
Parental pool - features
Temporal stability in allele frequencies
No Evidence of overfishing
Allowing for 4 - 8
years recruitment
Avg. 2,200 ind./year
49
(3%)
760
(27%)
1148
(38%)
536
(24%)
568
(21%)
793
(23%)
94
(6%)
2003/04 Families
n=1,596
Genetic baseline
families from 2003/2004
No. lobsters assigned
to 2003/04 families +
% in relation to lobster
caught by NELCO and
sent to QUB
2007/ 2008
2008/ 2009
2009/ 2010
2010/ 2011
2011/ 2012
2012/ 2013
2013/ 2014
Summary Results: impact assessment
V-notched lobsters (summer – spring)
Increasing landings
£544,8
16
£537,4
19
£584,9
22
£654,6
19
£666,8
87
£803,6
34
Summary Results: preliminary
Summary Results: preliminary
• Maturation peak: 7 – 9+ years from hatching for
“small” and “larger” lobsters respectively
• 60% (N=957) of 2003/2004 lobsters families
contributed between 1 and 20 (avg. 2) lobsters to
fishery from 2007 onwards – i.e. recruited locally
Summary Results: preliminary
• Recruitment for 63% of
families was spread over 2 to
6 years
Local recruitment pattern
24%
81%
NELCO
fishing area
Dispersal pattern – “north-south”
76%
19% NELCO
fishing area
Dispersal pattern (NCLFA & IoM)
9%
6%
NELCO
2003/04
families
?
?
?
Dispersal pattern (NCLFA & IoM)
?
Clyde?
NELCO
2003/04
families
Concluding remarks
• First measurable evidence for positive impact of V-
notching
• The Maine lobstermen haven been doing it right!
(records landings in 2015) V-notching does work!
• In comparison to other approaches (e.g.
supplemental stocking) – cheaper, more
effective and without risks i.e. “natural”
• Hatchery systems: bypass natural selection
(i.e. decreasing mortality at early stages) =
introduction of “less fit” genetic material into the wild
Concluding remarks
• Despite potential for dispersal, there seems to be
strong evidence for local recruitment
• Strong selection to stay close to suitable rocky
habitats
• Lobster larvae likely capable of “vertical” movement in
water column?
• Work is still ongoing (e.g. reliable estimates of
population size – extended pedigrees)
Acknowledgements
• Colin Nelson (NELCO’s Director – initiated discussions
with QUB) & all NELCO members
• QUB Fish Genetics Research Group: Andy Ferguson, John Taggart,
Rosaleen Hynes, Caroline Bradley, Maria Hughes, Sean Fitzpatrick,
Clio Surgenor, Amanda Kovalczyk
• AFBI: Carrie McMinn, Matt Service & Walter Crozier
• Beaufort Fish Genetics Team: Phil McGinnity & Tom Cross
• The Northern Ireland Fish Producers' Organisation Limited (NIFPO):
Dick James & Lynn Gilmore
• Department of Agriculture and Rural Development (DARD)
• Beaufort Marine Research Award in Fish Population Genetics,
funded by the Irish Government under the Sea Change Programme